Supporting means for an expansible container



SUPPORTING MEANS FOR AN EXPANSIBLE CONTAINER Filed Feb. 15, 1965 July 19, 1966 a. a. BENGTSSON 2 Sheets-Sheet 1 bfii /ununnllllllllllllllllll FIG.2

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SUPPORTING MEANS FOR AN EXPANSIBLE CONTAINER Filed Feb. 15, 1965 2 Sheets-Sheet 2 FIG.3

INVENTOR. Bengt Gunnam Bengtsson MJW & PM,

United States Patent 3,261,586 SUPPORTING MEANS FOR AN EXPANSIBLE CONTAINER Bengt Gunnar Bengtsson, Goteborg, Sweden, assignor to Aktiebolaget Gotaverken, Goteborg, Sweden, a corporation of Sweden Filed Feb. 15, 1965, Ser. No. 432,745 Claims priority, application Sweden, Mar. 7, 1964, 2,903/ 64 4 Claims. (Cl. Z48-346) The transportation, especially in ships, and storing of very cold or very warm media, usually liquids, brings about many major problems. One essential requirement is that the containertank--shall have freedom of thermal contraction and expansion in all directions. The container must also be supported in such a manner that undesired movements beside the necessary thermal displacements do not occur even during exceptional conditions, for instance the heavy rolling or pitching of a ship. Another essential requirement is an efiicient insulation of the container in relation to its surrounding, for instance the hull of the ship.

It has proven difficult to combine the desideratum of freedom of thermal movement with the requirement of fixation in relation to the support. Especially in those designs, where the thermal movements occur by the container directly sliding in relation to the support, it has been found that this sliding does not work smoothly but occurs in sudden jumps. These mean a serious danger to pipings, ventilation ducts or the like connected to the container. The risk of leakage, which may have disastrous consequences is also great. The jumpy movements may be explained partly by the weight of the loaded container and partly by the fact that the container, at points, may be bonded by freezing to the support.

It has been proposed to introduce shims or linings having a low coefiicient of friction between the container and the insulated support but this has made the container floating. This means that the container during motions of the seas loses its friction hold in relation to the support. This friction must, however, be retained for assisting the stabilizing of the container.

It has also been proposed to arrange support members in concentric circles around the fixed vertical central axis through the container. These permit an elastic deformation through sliding or rolling movements. The idea of locking the central axis of the container implies many advantages when compared with other solutions in that the container has freedom of movements in all directions. Hitherto known devices have, however, been complicated, expensive to manufacture and have not always worked well.

One object of the invention is to provide a design where the supporting members have a high insulating capacity whereby the total space required below the container for insulation and fixation may be reduced.

Another object of the invention is to produce a container which retains its friction hold with respect to the supporting members but nevertheless is able to perform limited movement-s caused by temperature deformation.

Another object of the invention is to arrange the components in such a manner that the thermal movement of the container in relation to the support will be compensated in an efficient and reliable manner which removes all risks of damage to the insulation or container as well as to the various conduits connected thereto.

A further object of the invention is to design the blocks forming the support in such a manner that they will roll in the direction of the temperature deformation, the height of the blocks being greater than the spacing between the blocks so that they, on no occasion, can be tilted to a horizontal position.

Another object of the invention is to keep the distance between the bottom of the container and the support constant by designing the contact surfaces of the blocks as parts of a common cylindrical surface.

A further object of the invention is to design the blocks in such a manner that it is easy to compensate irregularities and defects in the bottom of the container.

Other characterizing points and advantages will be evident from the following description with reference to the appended drawings which show an embodiment of the invention.

In the drawings:

FIGURE 1 shows a section of a ship provided with a container according to the invention.

FIGURE 2 is a section along line 11-11 in FIG- URE 1.

FIGURE 3 shows on a larger scale a section through the bottom of the container.

FIGURE 4 is a section along line IV-IV in FIG- URE 3.

FIGURE 5 shows a part enlargement of some of the carrying members in FIGURE 3 and the position they attain after a thermal movement of the container.

The containerthe tank 1shown in FIG. 1 preferably has a parallelepipedic shape and is, by means of a central bulkhead 2, subdivided into two rooms. The tank is surrounded by an insulating wrapping 3 in such a manner that a space, hereafter called cofferdam 4, is provided at the top and at the sides of the container. This cofferdam is arranged to contain further means 5 adapted to stabilize the container. It will serve as a receptacle during possible leakage of the container and also make possible an inspection on the outside of the container. The insulating Wrapping 3 is, towards the cofferdam 4, lined with a corrugated metal sheathing 6, acting as a barrier against fluid escaping from the container. The main object thereof is to prevent such fluid from coming into contact with the insulation and with the inner hull 15.

The bottom of the container 1 is supported by a number of members 7 arranged in concentric circles around the vertical central axis through the container. These members 7 consist of prismatic blocks having essentially plane parallel sides and rounded upper and lower contact surfaces. These rounded surfaces make it possible to take care of a limited movement of the container while the central axis 8 of the block shifts, for instance from a vertical to a somewhat inclined position (see FIG. 5).

The axis 8, which is the center of the circular-symmetric pattern of the blocks, is always fixed in relation to the support and as long as the friction coefiicient in the contact surface of the blocks does not pass beyond the maximum value as a result of forces acting in the longitudinal direction of the blocks the container can thus be given no tendency to turn or rotate in relation to its support.

Members 7 must of course be dimensioned and designed in such a manner that they will never attain an unstable position, i.e., the inclination must never be so great that the blocks may tilt over. If large temperature deformations are expected the blocks may be arranged with an inclination obverse to that which they will have after the temperature deformation of the tank. An insulating material 9, preferably consisting of elastic mattings of mineral wool is arranged in the space between the blocks. These mattings shall, besides their insulating function, support the blocks in an upright position and must well fill the space between the blocks even when this is deformed during the rolling movements of the blocks. It is always difiicult to make the support for the container as well as the bottom thereof absolutely plane and it is therefore necessary to provide means to compensate possible differences at each block. These are well adapted to be worked in respect of the height measure, and therefore an even carrying capacity is easily obtained along the bottom structure.

As is shown on FIGURE 5 the rounded surfaces of the block may consist of a half cylinder or they may be part only of a bigger diameter cylinder. As the contact between container and support must not be lost during the rolling movementof the blocks it is preferable that the upper and the lower contact surfaces form part of a common cylindrical surface the center of which is at the half height of the block. In this manner the distance between tank bot-tom and support remains unaltered irrespective of the inclination of the blocks.

When the blocks are made from wood the fibre direction is preferably arranged at right angles to the tank bottom in order that the biggest possible carrying capacity shall be obtained. The rounded surfaces may be sheathed by a stronger material than that of the blocks. The weight of the tank is, by way of the blocks 7, transferred first to pressure distributing plate-shaped members 10, and from these to wooden slats 11 which are arranged between corrugations 12 in the metal sheathing forming the secondary barrier 6.

This rests on hard fibre boards 13 which finally distribute the linear load from the blocks in such a manner that the insulating layers 14 therebelow will have to carry an evenly distributed load. Legend 15 denotes the double bottom of the hull which finally takes care of the load.

What I claim is:

1. Means for supporting a container adapted for receiving a cargo, the temperature of which differs widely from the ambient temperature, on a bottom structure in such a manner that an essentially vertical central axis through the container remains fixed in relation thereto, whereby movements caused by changes in temperature can take place in all directions from said fixed axis,

said means including a number of prismatic blocks with essentially plane vertical sides and rounded upper and lower contact surfaces arranged in such a manner between the container and the bottom-structure that for each block a plane intersecting said :block at right angles to the longitudinal axis thereof essentially passes through said fixed vertical axis,

the blocks being spaced from each other a distance which is less than the height of a block and supported in upright position by insulating material arranged between the blocks.

2. Means according to claim 1, in which the rounded contact surfaces of each prismatic block form part of a common cylindrical surface.

3. Means according to claim 1 in which the prismatic blocks are made of wood, with a fibre direction at right angles to the bottom of the container.

4. Means according to claim 1 in which the heat insulating material arranged between the blocks, consists of elastic matting having high rigidity transversely to the blocks.

References Cited by the Examiner UNITED STATES PATENTS 2,993,460 7/1961 Dreyer 114-74 FOREIGN PATENTS 892,044 3/ 1962 Great Britain.

CLAUDE A. LE ROY, Primary Examiner.

J. F. FOSS, Assistant Examiner. 

1. MEANS FOR SUPPORTING A CONTAINER ADAPTED FOR RECEIVING A CARGO, THE TEMPERATURE OF WHICH DIFFERS WIDELY FROM THE AMBIENT TEMPERATURE, ON A BOTTOM STRUCTURE IN SUCH A MANNER THAT AN ESSENTIALLY VERTICAL CENTRAL AXIS THROUGH THE CONTAINER REMAINS FIXED IN RELATION THERETO, WHEREBY MOVEMENTS CAUSED BY CHANGES IN TEMPERATURE CAN TAKE PLACE IN ALL DIRECTIONS FROM SAID FIXED AXIS, SAID MEANS INCLUDING A NUMBER OF PRISMATIC BLOCKS WITH ESSENTIALLY PLANE VERTICAL SIDES AND ROUNDED UPPER AND LOWER CONTACT SURFACES ARRANGED IN SUCH A 